Sheet-molded chip-scale package

ABSTRACT

Embodiments include but are not limited to apparatuses and systems including a microelectronic device including a die having a first surface and a second surface opposite the first surface, a conductive pillar formed on the first surface of the die, and an encapsulant material encasing the die, including covering the first surface, the second surface, and at least a portion of a side surface of the conductive pillar. Methods for making the same also are described.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation-in-part of U.S. patentapplication Ser. No. 12/207,206, filed Sep. 9, 2008, now U.S. Pat. No.8,030,770, and entitled “Substrateless Package,” the entire content anddisclosure of which is incorporated herein in its entirety.

TECHNICAL FIELD

Embodiments of the present invention relate generally to microelectronicdevices and more particularly to devices including dies and modulespackaged without carrier substrates.

BACKGROUND

In the current state of integrated circuit technology, an integratedcircuit device will often be in the form of a die or a chip. One or moredie sometimes will be mounted onto a carrier substrate to form apackage. Although carrier substrates may be suitable for manyapplications, it adds to the overall size and expense of the package.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be readily understood by thefollowing detailed description in conjunction with the accompanyingdrawings. To facilitate this description, like reference numeralsdesignate like structural elements. Embodiments of the invention areillustrated by way of example and not by way of limitation in thefigures of the accompanying drawings.

FIG. 1 illustrates a cross-sectional side view of a microelectronicdevice including a sheet-molded chip-scale-package having a die,conductive pillars formed on the die, and an encapsulant materialencasing the die and the conductive pillars, in accordance with variousembodiments of the present invention.

FIG. 2 illustrates a cross-sectional side view of anothermicroelectronic device including a sheet-molded chip-scale-packagehaving a die, conductive pillars formed on the die, and an encapsulantmaterial encasing the die and the conductive pillars, wherein a surfaceof the encapsulant material is below the level of the ends of theconductive pillars, in accordance with various embodiments of thepresent invention.

FIG. 3 illustrates a cross-sectional side view of anothermicroelectronic device including a sheet-molded chip-scale-packagehaving a die, conductive pillars formed on the die, and an encapsulantmaterial encasing the die and the conductive pillars, wherein theencapsulant material includes recesses around the conductive pillars, inaccordance with various embodiments of the present invention.

FIG. 4 illustrates a cross-sectional side view of anothermicroelectronic device including a sheet-molded chip-scale-packagehaving a die, another component, conductive pillars formed on the die,and an encapsulant material encasing the die, the other component, andthe conductive pillars, in accordance with various embodiments of thepresent invention.

FIGS. 5A-5H illustrate various stages of a method for making amicroelectronic device including a sheet-molded chip-scale-packagehaving a die, conductive pillars formed on the die, and an encapsulantmaterial encasing the die and the conductive pillars, in accordance withvarious embodiments of the present invention.

FIG. 6 illustrates a block diagram of a system incorporating amicroelectronic device such as, for example, one or more of the devicesillustrated in FIGS. 1-4, in accordance with various embodiments of thepresent invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof wherein like numeralsdesignate like parts throughout, and in which is shown by way ofillustration embodiments in which the invention may be practiced. It isto be understood that other embodiments may be utilized and structuralor logical changes may be made without departing from the scope of thepresent invention. Therefore, the following detailed description is notto be taken in a limiting sense, and the scope of embodiments inaccordance with the present invention is defined by the appended claimsand their equivalents.

Various operations may be described as multiple discrete operations inturn, in a manner that may be helpful in understanding embodiments ofthe present invention; however, the order of description should not beconstrued to imply that these operations are order dependent. Moreover,some embodiments may include more or fewer operations than may bedescribed.

The description may use the phrases “in an embodiment,” “inembodiments,” “in some embodiments,” or “in various embodiments,” whichmay each refer to one or more of the same or different embodiments.Furthermore, the terms “comprising,” “including,” “having,” and thelike, as used with respect to embodiments of the present invention, aresynonymous.

The term “coupled to,” along with its derivatives, may be used herein.“Coupled” may mean one or more of the following. “Coupled” may mean thattwo or more elements are in direct physical or electrical contact.However, “coupled” may also mean that two or more elements indirectlycontact each other, but yet still cooperate or interact with each other,and may mean that one or more other elements are coupled or connectedbetween the elements that are said to be coupled to each other.

The term “formed on,” along with its derivatives, may be used herein.“Formed on” in the context of a layer being “formed on” another layermay mean that a layer is formed above, but not necessarily in directphysical or electrical contact with, another layer (e.g., there may beone or more other layers interposing the layers). In some embodiments,however, “formed on” may mean that a layer is in direct physical contactwith at least a portion of a top surface of another layer. Usage ofterms like “top” and “bottom” are to assist in understanding, and theyare not to be construed to be limiting on the disclosure.

The term “active surface” as used herein may refer to the surface of adie having the active regions/areas, as is known to those having skillin the art. The active surface a die may include any one or more ofvarious circuitry components, such as transistors, memory cells, passivecomponents, and the like.

For the purposes of the present invention, the phrase “A/B” means A orB. The phrase “A and/or B” means “(A), (B), or (A and B).” The phrase“at least one of A, B, and C” means “(A), (B), (C), (A and B), (A andC), (B and C), or (A, B and C).” The phrase “(A)B” means “(B) or (AB),”that is, A is an optional element.

Various embodiments of the present invention are directed tomicroelectronic devices including a die having a first surface and asecond surface opposite the first surface, a conductive pillar formed onthe first surface of a die, and an encapsulant material, such as moldingmaterial and/or wafer-coating resin, encasing the die, includingcovering the first and second surfaces of the die and at least a portionof a side surface of the conductive pillar. In various embodiments, afirst end of the conductive pillar may be formed on the first surface ofthe die, and a solder bump may be directly coupled with a second end ofthe conductive pillar. Accordingly, in various embodiments, themicroelectronic device may be a chip-scale package or module.

A cross-sectional side view of an example microelectronic device 100 isillustrated in FIG. 1. As illustrated, the microelectronic device 100(also referred to as “device 100”) includes at least one die 102including a first surface 104 and a second surface 106 opposite thefirst surface 104. A plurality of conductive pillars 108 may be formedon the first surface 104, and an encapsulant material 110 such as amolding material may cover the first surface 104, the second surface106, and at least a portion of side surfaces 112 of the conductivepillars 108, to encase the die 102 and the conductive pillars 108, toform or begin to form a chip-scale package or module.

The first surface 104 may be an active surface. Although the illustratedembodiment shows the active surface as running the entire width of thedie 102, in alternate embodiments, the active surface 104 may run lessthan the entire width of die 102.

First ends 116 of the conductive pillars 108 may be directly coupledwith the first surface 104 of the die 102, and at least the second ends118 of the conductive pillars 108 may be free of the encapsulantmaterial 110. Solder bumps 114 may be directly coupled with the secondends 118 of the conductive pillars 108, as shown. The solder bumps 114may provide for electrical connection with the die 102 via theconductive pillars 108. In various embodiments, the device 100 may becoupled with a system-level board such as, for example, a printedcircuit board, by reflowing the solder bumps 114.

In some embodiments, the conductive pillars 108 comprise copper. Otherconductive material may be similarly suitable.

The encapsulant material 110 may be a molding material. Molding materialis sometimes referred to in the art as “mold compound,” and may be anyelectrically insulative encapsulant material known in the art suitablefor the purpose. For example, the molding material may be an epoxymaterial. In various other embodiments, however, the molding materialmay be one of plastic, ceramic, glass, and the like.

The encapsulant material 110 may comprise a first sheet 122 of theencapsulant material 110 on the second surface 106 of the die 102, and asecond sheet 124 of the encapsulant material 110 over the first surface104 and at least a portion of the side surfaces 112 of the conductivepillars 108, as shown in FIGS. 1-3. The first sheet 122 and the secondsheet 124 together encase the die 102 and the conductive pillars 108, toform or begin to form a chip-scale package or module. It is noted thatone or more operations on the device 100, whether during construction orthereafter, may result in the first sheet 122 and the second sheet 124becoming joined such that the sheets 122, 124 are no longer distinct, orare substantially indistinct. For example, heat, vacuum, or pressure mayhave the effect of fusing the sheets 122, 124 together.

As illustrated in FIG. 2 and FIG. 3, portions of the side surfaces 112of the conductive pillars 108 may be free of the encapsulant material210 (sheets 222, 224), 310 (sheets 322, 324) such that the solder bumps214 directly couple with those portions of the side surfaces 112. Forthe device 200 illustrated in FIG. 2, the surface of the second sheet224 of the encapsulant material 210 is below the level of the secondends 118 of the conductive pillars 108 so that portions of the sidesurfaces 112 are free of the encapsulant material 210, allowing thesolder bumps 214 to directly couple with those portions of the sidesurfaces 112 as shown. In other embodiments, as illustrated for thedevice 300 illustrated in FIG. 3, encapsulant material 310 in the area320 around the second ends 118 of the conductive pillars 108 may beremoved (by laser ablation, for example) to form recesses so that theportions of the side surfaces 112 of the conductive pillars 108 are freeof the encapsulant material 310, allowing the solder bumps 314 directlycouple to those portions of the side surfaces 112 as shown.

FIG. 4 illustrates another example of a microelectronic device 400 inaccordance with various embodiments. As illustrated, the device 400includes at least one die 102 and at least one other component 426. Oneor more conductive pillars 108 may be formed on the first surface 104 ofthe die 102 and the first surface 128 of the other component 426, and anencapsulant material 422, 424 may cover the first surfaces 104, 428, thesecond surfaces 106, 430 and at least a portion of the side surfaces 112of the conductive pillars 108, to encase the die 102, the othercomponent 426, and the conductive pillars 108, to form or begin to forma chip-scale package or module. Solder bumps 114 may be directly coupledwith the second ends 118 of the conductive pillars 108, as shown.

The other component 426 may be a passive device such as, for example, aresistor, an inductor, a diode, a low pass filter, a surface acousticwave (SAW) or bulk acoustic wave (BAW) device, or a capacitor. In someembodiments, the other component 426 may be another die.

An example method for forming a microelectronic device, such as, forexample, the device 100, 200, 300, or 400 illustrated in FIGS. 1-4,respectively, is illustrated in FIGS. 5A-5H by way of cross-sectionalside views of the device at various stages of the method. It should benoted that various operations discussed and/or illustrated may begenerally referred to as multiple discrete operations in turn, to helpin understanding embodiments of the present invention. The order ofdescription should not be construed to imply that these operations areorder dependent, unless explicitly stated. Moreover, some embodimentsmay include more or fewer operations than may be described.

As illustrated in FIG. 5A, a die 102 including a first surface 104 isprovided. The first surface 104 may be an active surface.

In FIG. 5B, conductive pillars 108 are formed on the first surface 104.As discussed herein, the conductive pillars 108 may comprise copper oranother suitable material.

In some embodiments, an optional cap layer (not illustrated herein) maybe formed on top surfaces of the conductive pillars 108. The cap layermay be removed at another stage of the method (as discussed more fullybelow), and thus the cap layer may be a material selected to be easilyremoved or removed with minimal cost. In general, the cap layer mayserve to protect the conductive pillars from exposure (e.g., to minimizeoxidation or damage to the top surfaces of the conductive pillars 108).Although any material, in general, may be suitable for forming the caplayer, tin may be a suitable option in some embodiments. Other materialmay be similarly suitable.

In FIG. 5C, one or more of the dies 102 may be placed onto a first sheet122 of the encapsulant material such that a second surface 106 of thedie 102 is covered by the first sheet 122. Any suitable carrier 532 maybe used for facilitating the handling of the first sheet 122 ofencapsulant material and the dies 102.

Prior to placing the die 102 onto the first sheet 122, the first sheet122 of encapsulant material may be warmed such that the encapsulantmaterial becomes tacky, which may facilitate the adhesion of the dies102 to the first sheet 122.

In various embodiments, rather than being a molding material, the firstsheet 122 may instead be a temporary adhesive film to temporarily holdthe die 102 in place during one or more subsequent operations. In theseembodiments, encapsulant material may be formed on the second surface106 of the die 102 in a subsequent operation, as discussed more fullybelow. The temporary adhesive film may be a thermally-releasabletemporary tape that releases from the die 102 when heated above acertain temperature.

In some embodiments, at least one other component in addition to the die102 may be provided, as described herein with reference to FIG. 4.

A second sheet 124 of encapsulant material may be formed over the die102, as shown in FIG. 5D, such that the die 102 and at least a portionof the side surfaces 112 of the conductive pillars 108 are encased inthe encapsulant material.

The second sheet 124 of encapsulant material may be formed over the die102 by any suitable method including, but not limited to, lamination. Asshown in FIG. 5D, a press 534 may press-laminate the second sheet 124 ofencapsulant material onto the die 102. The press lamination may beperformed under vacuum and/or heat, which may provide, in someembodiments, void-free or substantially-void-free lamination.

In other embodiments, the second sheet 124 may be roll-laminated by aroller 536 as shown in FIG. 5E. The roll-lamination may be performedunder vacuum and/or heat, which may provide, in some embodiments,void-free or substantially-void-free lamination.

After the second sheet 124 is laminated onto the die, a curing operationmay be performed to cure the encapsulant material.

As illustrated in FIG. 5F, the second sheet 124 of the encapsulantmaterial may be formed such that the second ends 118 conductive pillars108 are no longer exposed. To expose the second ends 118 of theconductive pillars 108, a portion of the second sheet 124 may be removedto expose the second ends 118. In some embodiments, portions of the sidesurfaces 112 of the conductive pillars 108 may also be exposed, as shownin FIG. 2 or FIG. 3, for example. Removal of the portion of the secondsheet 124 may be performed by laser ablation or grinding, or anothersuitable method. During the operation for removing the portion of thesecond sheet 124 to expose the second ends 118 of the conductive pillars108, it may be desirable to remove a small amount of the second ends 118of the conductive pillars 108 to provide a clean, even surface, butdoing so is not required.

In some embodiments, a thickness of the second sheet 124 of theencapsulant material, when initially formed, may be controlled so thatthe second ends 118 of the conductive pillars 108 are not covered. Forexample, the second sheet 124 may be formed so the surface of the secondsheet 124 is level with the second ends 118, as shown in FIG. 5G, orbelow the level of the second ends 118, as shown in FIG. 2.

For embodiments in which the first sheet 122 is a temporary adhesivefilm, the assembly may be heated above a release temperature of thetemporary adhesive film to release the die 102 from the first sheet 122.The second surface 106 of the die 102 may then be covered by anencapsulant material. In various embodiments, the second surface 106 ofthe die 102 may be covered by a molding material using a suitable methodsuch as, for example, one of those illustrated in FIG. 5D or FIG. 5E. Invarious embodiments, the second surface 106 of the die 102 may becovered by a wafer-coating resin by screen printing or another suitableoperation.

Solder bumps 114 may be directly coupled to the second ends 118 of theconductive pillars 108, as shown in FIG. 5H. For embodiments in whichportions of the side surfaces 112 of the conductive pillars 108 are freeof the encapsulant material, the solder bumps 114 may also be directlycoupled to the side surfaces 112 of the conductive pillars 108, as shownin FIG. 2 and FIG. 3.

A singulation operation may then be performed to separate the devicesinto individual devices, such as one of the devices 100, 200, or 300shown in FIG. 1, FIG. 2, or FIG. 3, respectively.

Embodiments of devices described herein, and apparatuses including suchdevices, may be incorporated into various other apparatuses and systems.A block diagram of an example system 600 is illustrated in FIG. 6. Thesystem 600 may include a microelectronic device 602 and an antenna 636.The device 602 may include, among other things, a die having a firstsurface and a second surface opposite the first surface, a conductivepillar formed on the first surface of the die, and an encapsulantmaterial encasing the die, including covering the first surface andsecond surface of the die and at least a portion of a side surface ofthe conductive pillar. The device 602 may be, for example, a device suchas one of devices 100, 200, 300, or 400 as illustrated in FIGS. 1-4,respectively.

In various embodiments, the device 602 may be configured to facilitatetransmission and reception of signals, and the antenna 636 may beoperatively coupled, but not necessarily directly coupled, to the device602 to transmit and receive signals.

As the device 602 may have smaller dimensions relative to variousrelated art devices including a carrier substrate, the system mayadvantageously be incorporated into electronic devices, including mobilephones and other portable electronic devices. The device 602 may, insome embodiments, be modular in configuration such that it includes morethan one die, one or more passive components, and possibly one or moreother associated components. Although the system may be incorporatedinto any number of electronic devices, some suitable portable electronicdevices may include a laptop computer, a personal digital assistant, agaming device, a music player, a video player, and the like.

Although certain embodiments have been illustrated and described hereinfor purposes of description of the preferred embodiment, it will beappreciated by those of ordinary skill in the art that a wide variety ofalternate and/or equivalent embodiments or implementations calculated toachieve the same purposes may be substituted for the embodiments shownand described without departing from the scope of the present invention.Those with skill in the art will readily appreciate that embodiments inaccordance with the present invention may be implemented in a very widevariety of ways. This application is intended to cover any adaptationsor variations of the embodiments discussed herein. Therefore, it ismanifestly intended that embodiments in accordance with the presentinvention be limited only by the claims and the equivalents thereof.

What is claimed is:
 1. An apparatus comprising: a die having a firstsurface and a second surface opposite the first surface; a conductivepillar formed on the first surface of the die; and an encapsulantmaterial encasing the die, including covering the first surface, thesecond surface, and at least a portion of a side surface of theconductive pillar; wherein the encapsulant material comprises: a firstsheet of the encapsulant material attached to the second surface of thedie; and a second sheet of the encapsulant material laminated over thefirst surface of the die such that the die and the at least the portionof the side surface of the conductive pillar is encased in theencapsulant material.
 2. The apparatus of claim 1, wherein a first endof the conductive pillar is directly coupled with the first surface ofthe die, and wherein a second end of the conductive pillar is free ofthe encapsulant material.
 3. The apparatus of claim 2, furthercomprising a solder bump directly coupled with the second end of theconductive pillar.
 4. The apparatus of claim 2, wherein another portionof the side surface adjacent to the second end of the conductive pillaris free of the encapsulant material.
 5. The apparatus of claim 4,wherein a solder bump is directly coupled with the second end of theconductive pillar and the other portion of the side surface of theconductive pillar.
 6. The apparatus of claim 1, further comprising apassive component, and wherein the encapsulant material further encasesthe passive component.
 7. The apparatus of claim 1, wherein theencapsulant material comprises a first encapsulant material and a secondencapsulant material different from the first encapsulant material,wherein the first surface of the die and the at least the side surfaceof the conductive pillar is covered by the first encapsulant material,and wherein the second surface of the die is covered by the secondencapsulant material.
 8. The apparatus of claim 7, wherein the firstencapsulant material is a molding material and wherein the secondencapsulant material is a wafer-coating resin.
 9. A method comprising:providing a die having a first surface, a second surface opposite thefirst surface, and a conductive pillar on the first surface of the die;and forming an encapsulant material on the first surface, the secondsurface, and at least a portion of a side surface of the conductivepillar to encase the die and the conductive pillar; wherein forming ofthe encapsulating material comprises: attaching the second surface ofthe die to an adhesive material; covering the first surface of the diewith a first encapsulant material such that the die and the at least theportion of the side surface of the conductive pillar is encased in thefirst encapsulant material; after the covering, detaching the secondsurface of the die from the adhesive material; and covering the secondsurface of the die with a second encapsulant material.
 10. The method ofclaim 9, wherein the providing includes directly coupling a first end ofthe conductive pillar with the first surface of the die, and wherein themethod further comprises directly coupling a solder bump with a secondend of the conductive pillar.
 11. The method of claim 10, furthercomprising, before the directly coupling of the solder bump, laserablating the second end of the conductive pillar to clean the second endof the conductive pillar.
 12. The method of claim 10, furthercomprising, before the directly coupling of the solder bump, removing aportion of the molding material to expose the second end of theconductive pillar.
 13. The method of claim 10, further comprising,before the directly coupling of the solder bump, removing a portion ofthe encapsulant material to expose the second end of the conductivepillar.
 14. The method of claim 10, further comprising directly couplingthe solder bump with another portion of the side surface of theconductive pillar which is adjacent to the second end of the conductivepillar.
 15. The method of claim 9, wherein the first encapsulantmaterial is a molding material and wherein the second encapsulantmaterial is a wafer-coating resin.
 16. The method of claim 9, furthercomprising providing a passive component, and wherein the forming of theencapsulant material includes forming the encapsulant material over thepassive component.
 17. A system comprising: a microelectronic deviceconfigured to facilitate transmission and reception of signals, themicroelectronic device including: a die having a first surface and asecond surface opposite the first surface; a conductive pillar formed onthe first surface of the die; and an encapsulant material encasing thedie, including covering the first surface, the second surface, and atleast a portion of a side surface of the conductive pillar; and anantenna operatively coupled to the microelectronic device to transmitand receive the signals; wherein the encapsulant material comprises: afirst sheet of the encapsulant material attached to the second surfaceof the die; and a second sheet of the encapsulant material laminatedover the first surface of the die such that the die and the at least theportion of the side surface of the conductive pillar is encased in theencapsulant material.
 18. The system of claim 17, wherein the system isa mobile phone, a smart phone, a laptop computer, a personal digitalassistant, a gaming device, a music player, and a video player, a radardevice, or a satellite communication device.